The present invention relates generally to combustion control devices and particularly to a device for regulating the combustion of a nozzle spray type burner which is used as a heat source for an infrared ray heating device.
Conventional infrared ray emission or heating devices are constructed, for example, as shown in FIG. 1. A burner body or housing 1 encloses a fan 2, and forms an intake passage 3 and an exhaust passage 4 for directing combustion air to and away from the fan. A fuel spray nozzle 5 is provided in the region of the outlet of the exhaust passage 4. A fuel pump 6 feeds liquid fuel such as kerosene to the nozzle 5, and a discharge electrode 7 spaced from the nozzle 5 forms a predetermined discharge gap between the electrode 7 and the nozzle 5 for ignition purposes.
A butterfly valve 8 is provided in the intake passage 3 for controlling the combustion air. More particularly, valve 8 controls the rate of flow of the air for combustion which is fed into a combustion chamber 10 associated with an infrared ray heating device 9, the device 9 being coupled to the outlet of the exhaust passage 4. An insulating material 11 forms a part of the combustion chamber 10, and a heat generating member 12 forming a wall of the combustion chamber 10 provides a heat generating or emitting surface associated with the infrared ray heating device 9.
In the conventional heating device constructed as above, the fan 2 operates to send air for combustion purposes into the combustion chamber 10, while the fuel pump 6 operates to supply liquid fuel which is sprayed into the air flow through the nozzle 5 for combustion within the combustion chamber 10. As the heat generating member 12 is heated to a red heat condition, infrared rays are emitted therefrom. The combustion within the burner may be regulated to vary the amount of infrared ray emission. However, in the prior art heaters, the fuel supply system and the air supply system were constructed independently of each other, therefore making it extremely difficult to change the degree of combustion.
According to the prior art, the butterfly valve 8 was fixed in such a way as to assure a flow of air in an amount corresponding to the amount of the fuel sprayed through the fuel spray nozzle 5, thereby preventing the combustion flames from extinguishing or producing soot.
Accordingly, a so-called ON-OFF type of control provided by a thermostat or manual operation was relied upon in order to regulate the room temperature, since it was virtually impossible to control the infrared ray emission, or the heat generated by the burner.
However, the conventional heaters had the disadvantage that when this ON-OFF type of control occurred, the balance between the air and the fuel was quite easily disturbed upon ignition of the air-fuel mixture or extinguishing the combustion flame, thereby resulting in the creation of soot, or even the generation of foul odors. Also, differences in room temperature between the times the combustion flame was present or extinguished became unduly large.
An object of the present invention is to overcome the above defects of the prior art.
Another object of the present invention is to provide a combustion control device for a nozzle spray type burner wherein the flow rate of combustion air and the amount of fuel sprayed into the combustion chamber are simultaneously controlled, a first mechanism of the device which controls the flow rate of the combustion of air being interconnected with a second mechanism of the device which controls the amount of fuel sprayed into the combustion chamber.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.